A Wideband Dual-Polarized Achromatic Reflective Metasurface Using ME-Dipole Elements

In this paper, we present a wideband dual-polarized achromatic reflective metasurface based on a modified wideband magnetoelectric (ME) dipole unit cell. Two folded striplines are introduced to terminate the ME-dipole unit cell to control both the phase and group delays over a broad bandwidth. The designed unit cell achieves $\mathbf{\gt 9 0 \%}$ reflection efficiency for both polarizations and -15 dB polarization isolation within the working frequency of $\mathbf{8 - 1 2} \mathbf{~ G H z ~ (4 0 \% ~ b a n d w i d t h)}$.A phase coverage of 1000° (which parlays into achromatic performance) is achieved at the center frequency. We demonstrate the concept by designing an achromatic metasurface reflecting a normally incident plane wave to $\theta_{r}=20^{\circ}$ over the entire the frequency band, with no angular dispersion. The simulation results show that the reflection angle of the proposed metasurface stays stable across the working frequency band compared to a traditional metasurface. The proposed metasurface has potential to achieve reconfigurability in the future.